﻿using System;

namespace App
{
    class Program
    {
        public static long num1, num2;
        static void Main(string[] args)
        {
            string input = "";
            while (true)
            {
                Console.WriteLine("请选择要进行的计算：     1.+  2.-  3.*  4./");
                input = Console.ReadLine();
                int c;
                
                Console.WriteLine("请输入要计算的两个数:");
                num1 = Int64.Parse(Console.ReadLine());
                num2 = Int64.Parse(Console.ReadLine());
                switch (input)
                {
                    case "1":
                        Add(num1, num2);
                        break;
                    case "2":
                        Minus(num1, num2);
                        break;
                    case "3":
                        Multiply(num1, num2);
                        break;
                    case "4":
                        Divide(num1, num2);
                        break;
                    default:
                        Console.WriteLine("请输入正确的数字！");
                        break;
                }
            }

            Console.ReadKey();
        }
        
        public static void Add(long a, long b)
        { 
            Console.WriteLine("{0} + {1} = {2}", a, b, a + b);
        }
        public static void Minus(long a, long b)
        {
            Console.WriteLine("{0} - {1} ={2}", a, b, a - b);
        }
        public static void Multiply(long a, long b)
        {
            Console.WriteLine("{0} * {1} ={2}", a, b, a * b);
        }
        public static void Divide(long a, long b)
        {
            Console.WriteLine("{0} / {1} ={2}", a, b, a / b);
        }
    }
}
